Carbon Black-LaCoO3 Composite Material as Counter Electrode for Quasi-Solid-State Dye-Sensitized Solar Cell
Dye-sensitized solar cell (DSSC) is considered as the next generation low cost photovoltaic device, and one of the important components is the counter electrode which reduces the I3- ions generated after electron injection from iodide into the oxidized sensitizer. In this work composite material of carbon black and LaCoO3 synthesized by sol-gel method has been investigated to replace the platinized counter electrode for quasi-solid-state dye-sensitized solar cells. From cyclic voltammogram, it was found that carbon black catalyzed with LaCoO3 exhibited increased reduction current compared with that of carbon black without LaCoO3. This was consistent with increased surface roughness depicted from scanning electron microscopy (SEM) image. The electrochemical impedance spectroscopy (EIS) of DSSCs using carbon black-LaCoO3 composite as counter electrode revealed lower charge-transfer resistance (Rct) than that using carbon black. The highest conversion efficiency of 5.40% was obtained from DSSC (active area 1 cm2) fabricated with quasi-solid composite polymer electrolyte using carbon black-LaCoO3 (95:5 ratio by weight) compared to 5.23% obtained from DSSC equipped with platinum counter electrode. The performances of the quasi-solid-state DSSCs sensitized with N719 and natural dyes were examined and it was concluded that the carbon black-LaCoO3 composite was compatible with platinum coated counter electrode for DSSCs.
Yuan Ming Huang
V. Somsongkul et al., "Carbon Black-LaCoO3 Composite Material as Counter Electrode for Quasi-Solid-State Dye-Sensitized Solar Cell", Materials Science Forum, Vols. 663-665, pp. 451-454, 2011